New Worlds: Fictive Kinship

(This post is part of my Patreon-supported New Worlds series.)

Fictive kinship is exactly what it sounds like: fictional kinship. Not the kind you find in novels (well, you may find it in a novel), but rather the kind that has no genetic component: it is, after a fashion, “made up.”

But it would be wrong to consider these relationships anything less than real. Fictive kinship can be profoundly important on an individual or a societal level. Anybody who’s ever seen the term “family of choice” floating around fandom knows that blood isn’t the only thing that can make a relationship narratively powerful; many of you have probably experienced it in real life, too. But fictive kinship isn’t simply a matter of being emotionally close to someone. It’s a formalized connection that’s recognized by the rest of your society.

There’s a sense in which you could call marriage the most common and accepted form of fictive kinship. After all, it creates a new relationship out of thin air, usually (at least these days) with no meaningful degree of blood relationship at all; doesn’t that count? As anthropologists use the term, though, fictive kinship lacks both consanguinity and affinity (i.e. marital connection). It’s basically the “miscellaneous” drawer for relationships that are thought of in familial terms, but aren’t those other kinds of family.

With marriage laid aside, the most widespread and familiar form of fictive kinship is adoption or fosterage. It creates a legal (or at least formalized) parent/child relationship where none existed before. The reasons for this can be manifold: nowadays the most common ones are either that the parents died, or that they’re are unable or unfit to care for their children. But grown adults can be adopted, too. Japanese history offers many examples of families without sons — or with unsuitable sons — adopting someone else to be their heir; sometimes this was a cousin from some more distant branch of the family, but in other cases the adoptee was simply an agreeable young man. If the family had an available daughter, the he might marry her as part of the adoption process, becoming a son-in-law and then a son. The lack of a blood relationship didn’t matter nearly as much in that society as it tended to in Europe, where laws might mandate that only the issue of your body could be counted as your heir.

Fosterage is a slightly different affair. It still creates a type of parent/child relationship, but without transferring legal connection away from the birth parents. The historical model is different from modern foster care; instead of being an alternative to structures like orphanages or an on-ramp to (ideally) formal adoption, it was a way of building social bonds between families. Fosterage might go in a number of directions: in the Celtic regions of the British Isles and in Iceland, higher-ranking individuals fostered their children to the households of their underlings. In other cases, a favored underling might be given the chance to send one of their children for fostering in the household of their superior, giving that child a leg up for future social advancement. Or it might happen between equals, particularly with an eye toward future marriage alliances.

By contrast, marriage alliances have often been prohibited between people related by milk instead of blood. Prior to the invention of modern baby formula, a number of women were employed as wet nurses, i.e. responsible for breast-feeding other women’s children. This could happen because ill health (physical or mental) or insufficient production meant the birth mother couldn’t adequately feed her own baby, but it also happened a fair bit among elite women. Some of them didn’t want to spend their time nursing; others were pressured away from doing so because nursing reduces fertility, and therefore means it will probably be longer before the woman gets pregnant again. (For elite men determined to get a male heir, that was a major concern.)

As with fosterage — of which this can be a type — milk kinship builds social bonds. Choosing a suitable wet nurse was quite an undertaking, because she was responsible not just for the health but often the rearing and education of the child; some people believed her moral character would be passed along in her milk. The lower-status families who fostered a child during the nursing years acquired a special connection to the higher-status family, because they became the fictive kin of that child. This fiction sometimes carried every bit as much weight as a blood relationship: Islam prohibits sexual contact between a man and his wet nurse, and some branches extend that to all the immediate consanguineous kin of the wet nurse, so that (for example) a man cannot wed his wet-nurse’s daughter, either. She is effectively his sister. “Milk siblings” are especially a thing when two children were nursing at the same time, one fostered, one the wet nurse’s own child.

Then you have godparents, whose role varies widely depending on which community you’re looking at. It’s largely a Christian concept, though there are somewhat analogous things in other religions; they stand as formal witnesses during baptism, and afterward are considered to have a lasting responsibility toward the one baptized. The familial nature of that relationship particularly comes to the forefront when you realize that godparents are prohibited from marrying their godchildren, just as if they were related by blood.

Fictive kinship can go beyond these familiar categories. My parents never fostered my best friend, much less formally adopted her, but somewhere along the line they took to introducing her as their “other daughter,” and I refer to her as my sister often enough that it was weird for me to type “my best friend” at the beginning of this sentence. Other kinds of mentorship beyond the spiritual responsibility of a godparent can acquire significance; the “cap parent” or eboshi-oya in the Japanese coming-of-age ceremony could be very important, and the child might use one of the characters from the cap parent’s name in their own adult name. Speculative fiction has even more room to invent new types of relationship that could fit into this category — what if your magic was somehow inherited from another, unrelated person, rather than through family lines? The possibilities are endless.

Do you have any fictive kin of your own? Or know anyone who does?

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About Marie Brennan

Marie Brennan is a former anthropologist and folklorist who shamelessly pillages her academic fields for inspiration. She recently misapplied her professors' hard work to the short novel Driftwood and Turning Darkness Into Light, a sequel to the Hugo Award-nominated Victorian adventure series The Memoirs of Lady Trent. She is the author of several other series, over sixty short stories, and the New Worlds series of worldbuilding guides; as half of M.A. Carrick, she has written The Mask of Mirrors, first in the Rook and Rose trilogy. For more information, visit, Twitter @swan_tower, or her Patreon.


New Worlds: Fictive Kinship — 13 Comments

  1. My husband and I are only children. We have “adopted” some of our close friends as our son’s “uncles” (with their agreement).

    It’s a way to give him more adults to reach out to and to acknowledge with a title the role they were playing anyway. I think it’s one of the better ideas we’ve had as parents.

    • It seems to be fairly common these days, at least among my own generation. I wonder how much that’s an outgrowth of using kinship terms as a form of respectful address, or if it’s at all driven by the decline in average family size, such that people have fewer blood-related aunts and uncles to fill that role in their lives. (I have only three pair total, counting both sides of my family, and none of them have ever lived anywhere near me.)

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  3. It’s worth considering how queer people build/have always built families when their blood or legal/adoptive families rejected them, and just the way that general cultural models vary widely in how much fictive kin gets associated (e.g., African-American culture often has a sprawling definition of family, South Asians in certain communities call pretty much every woman of a certain age older than one “auntie” whether related or not, etc.).

    • The use of terms like “auntie” as respectful address came up before, yeah. The “family of choice” thing is interesting, too — I think I’m going to wind up talking about it some when I get to residence patterns, i.e. who lives where and how a household is constituted.

  4. In academia, the PhD advisor is regarded as a scientific parent. This is especially evident in the German word Doktorvater (and, of course, Doktormutter) or the many genealogy projects. One of the oldest online is the math genealogy project at, while possibly the youngest is

  5. Very rare today, but very meaningful in warrior cultures is the concept of blood-brotherhood (or sisterhood). It reaches across the world, from Scandinavia – Sigurd, Gunther and Hogni in the Saga of the Volsungs (though there it’s a consequence of Sigurd’s marriage to their sister, Gudrun) to Mongolia – with Genghis Khan having had Jamukha as his ‘Anda’ or blood brother.
    I think my favorite portrayal of this trope in fiction was in Mercedes Lackey’s The Oathbound, where Tarma shena Tale’sedrin, the last of the Tale’sedrin clan, became blood-sisters with Kethryveris – allowing Kethry to join her very insular people, the Shin’a’in, and help Tale’sedrin be reborn as a clan.

    • !!! I can’t believe I forgot about that one. (One of the characters I played in an RPG even swore blood brotherhood to another character!) And yeah, I liked the Tarma/Kethry bond a lot.

      Hmmm, and that also makes me think of the soul bonds in Elfquest. Most of those go hand-in-hand with affinal relationsships, but Cutter and Skywise are referred to as soul-brothers. . . . and now I’m trying to recall if there are any other examples of that in the canon, because the waters of “affinal relationship or not” are muddied by the fact that the writers have openly confirmed that Cutter and Skywise have also slept together. In that particular case, “brothers” just might be the term used because they cannot, in a reproductive sense, be “mates.”

      • I personally really enjoy fiction where soul bonds exist, but are not necessarily connected to romantic love. There was a great fanfiction I once read, which was basically what if the Harry Potter Universe had soul bonds, and it had soul bonds ranging from love to brotherhood to parental relationships.

  6. Did Roman Emperors used to do that – adopt their successor, so technically the right to “wear the purple” would stay in the family?

    My sister had a number of non-fostered friends she called her sisters…a few who called her parents theirs & their parents hers, and some were just good friends (who may’ve gotten the title “sister” because they and she were all friends with the aforementioned other friends.

    Fosterage can be for ulterior motives as well – in the Incan Empire, the kids of local nobility (at least from the areas only recently added to the Empire) were brought to & fostered in the home of the Incan Empire, just like the local gods were — and for the same reason: to hold both kids and gods as hostages to ensure good behavior.

    • Did Roman Emperors used to do that – adopt their successor, so technically the right to “wear the purple” would stay in the family?

      Maybe? That sounds familiar, but I can’t swear my thoughts on the matter aren’t being contaminated by Ada Palmer’s Terra Ignota series, where that definitely happens. Then again, the people who do it are sort of neo-Roman, so it’s entirely possible it happened in the original imperial Rome, too.

      And good point re: hostile fosterage; I meant to bring that up and forgot.